[LTP] [PATCH] syscalls/prctl04: Fix false positive report when SECCOMP_MODE_FILTER is not supported

[He Zhe]

The child process really should not receive the expected siganl, SIGSYS, when
kernel doesn't support SECCOMP_MODE_FILTER.

This patch makes the child process exit with 1 to indicate such case.

Before this patch:
root@xilinx-zynq:~# /opt/ltp/testcases/bin/prctl04
tst_test.c:1431: TINFO: Timeout per run is 0h 05m 00s
---- snip ----
prctl04.c:154: TCONF: kernel doesn't support SECCOMP_MODE_FILTER
prctl04.c:154: TCONF: kernel doesn't support SECCOMP_MODE_FILTER
prctl04.c:154: TCONF: kernel doesn't support SECCOMP_MODE_FILTER
prctl04.c:204: TFAIL: SECCOMP_MODE_FILTER permits exit() unexpectedly
prctl04.c:154: TCONF: kernel doesn't support SECCOMP_MODE_FILTER

After this patch:
root@xilinx-zynq:~# /opt/ltp/testcases/bin/prctl04
tst_test.c:1431: TINFO: Timeout per run is 0h 05m 00s
---- snip ----
prctl04.c:154: TCONF: kernel doesn't support SECCOMP_MODE_FILTER
prctl04.c:154: TCONF: kernel doesn't support SECCOMP_MODE_FILTER
prctl04.c:154: TCONF: kernel doesn't support SECCOMP_MODE_FILTER
prctl04.c:154: TCONF: kernel doesn't support SECCOMP_MODE_FILTER

Signed-off-by: He Zhe <zhe.he@windriver.com>
---
 testcases/kernel/syscalls/prctl/prctl04.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/testcases/kernel/syscalls/prctl/prctl04.c b/testcases/kernel/syscalls/prctl/prctl04.c
index b9f4c2a10..868b35a29 100644
--- a/testcases/kernel/syscalls/prctl/prctl04.c
+++ b/testcases/kernel/syscalls/prctl/prctl04.c
@@ -158,12 +158,14 @@ static void check_filter_mode(int val)
 
 	TEST(prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &strict));
 	if (TST_RET == -1) {
-		if (TST_ERR == EINVAL)
+		if (TST_ERR == EINVAL) {
 			tst_res(TCONF,
 				"kernel doesn't support SECCOMP_MODE_FILTER");
-		else
+			exit(1);
+		} else {
 			tst_res(TFAIL | TERRNO,
 				"prctl(PR_SET_SECCOMP) sets SECCOMP_MODE_FILTER failed");
+		}
 		return;
 	}
 
@@ -208,7 +210,7 @@ static void verify_prctl(unsigned int n)
 			return;
 		}
 
-		if (tc->pass_flag == 2)
+		if (!(WIFEXITED(status) && WEXITSTATUS(status) == 1) && tc->pass_flag == 2)
 			tst_res(TFAIL,
 				"SECCOMP_MODE_FILTER permits exit() unexpectedly");
 	}
-- 
2.25.1